This research will lead to a new X-Ray tube that will enable CT scanners to operate continuously with no cool down delay time. Use of the new tube will improve CT imaging quality by allowing an unlimited number of slices to be obtained on a patient during a single session in the CT scanner, and will increase patient throughput. The new X- Ray tube will have 10 times the life of existing tubes, since its rotation bearings are outside the tub vacuum. The new tube can be retrofitted into half of the CT scanners currently in use to upgrade their performance. The new X-Ray tube uses a patented cooling approach from high power radar and satellite communication tubes. The enabling cooling technology was demonstrated in Phase I. X-Ray tubes with the new cooling technology, suitable for retrofitting into CT scanners, will be demonstrated in Phase II. PROPOSED COMMERCIAL APPLICATION: The new X-ray tube can be retrofitted into over half of the CT scanners currently in use, to upgrade their performance and extend their useful life. The upgraded CT scanners will provide better image quality, and by increasing patient throughout, will reduce CT scanning cost per patient.